Every Mac comes installed with Apple”˜s simple and useful application, Preview. Typically this application is used as the default program for viewing PDF’s, but this application can also be used to preview and edit photos. That’s right, some of the same basic editing and adjustment tools that you find in iPhoto or Photoshop are present in Preview.

So if you have iPhoto installed, why would you want to bother with Preview? Well sometimes, if you need to do some quick editing of a photo before you email it or print it out and don’t feel like opening iPhoto or another larger program, Preview comes in handy.

Preview has editing tools for rotating and resizing images, as well as making basic exposure and color adjustments and conversions.

Opening Photos In Preview

When you click on an image file, it will open in Preview, unless the image is a RAW photo file. You can also simply drag one or more image files to the Preview icon in the Dock and they will launch in the application.

I didn’t realize this before writing this article, you can also import images directly from your camera or scanner using Preview. When you save selected photos to a designated folder, they will open in Preview, providing a lightweight space for managing your images.

And for you shutterbugs out there, don’t think you can”˜t get basic EXIF or IPTC information about your images opened in Preview. That info is under Tools>Show Inspector. The Inspector also includes a way to add keywords that will get embedded in selected image files.

Editing Photos In Preview

In the Preview menu bar, most all the image editing tools are found under the Tools menu, which includes tools for rotating and flipping images, and even adding shapes and texts on top of an image.

The Adjust Size tool allows you to change the image dimensions and resolution. It even includes some default web pixel sizes, but unfortunately there’s no way to save your own custom settings.

As you will see, this resize tool also resamples your image and scales it proportionally, just as you do in iPhoto and Photoshop. This is very convenient if you need to quickly resize photos for web posting. At the bottom of the tool dialogue box, notice that you also get information about the resulting size of an image when its dimensions are changed.

Exposure & Color Adjustments

The heart of Preview”˜s adjustment tool is found by clicking the Adjust Color item in the Tool menu. Don’t be fooled by the name for this item. It does more than adjust colors of a photo. It more importantly allows you to adjust the exposure of images, so if they are too light or dark you can make corrections with this tool.

If your image is too light or dark, or if it’s lacking detail in the shadows and highlights, try using the Exposure slider to make those exposure adjustments.

Most digital images can typically can increased contrast and to help bring in more detail in the photo, so give the Contrast slider a try and see how it affects your photo.

Converting To Black & White Or Sepia

If you need a quick way to convert a color photo to black-and-white or sepia, simply move the Saturation slider all the way to the left to remove the color in the photo. This tool is not as advanced as in Photoshop, but for a down and dirty conversion to monochrome, this technique may well come in handy. Likewise, you can convert an image to sepia by using the Sepia slider.

The Temperature slider can add a little warmth to your image or cool it down, while the Tint overlay tool provides a color overlay to an image.

And finally, the last step you’ll want to make in your adjustment is sharpening. In my experience, the Sharpness slider works just as good in Preview as it does in iPhoto. So once you do all the exposure and color adjustments to an image, you can sharpen it up.

Oh, and one more thing. If you need to add some font style text, or draw an arrow, oval, or rectangle in an image, Preview has you covered there too. Click on Annotate in the Tools menu for what you need. These annotations are layered on top of the image, of course, and they can be selected and edited out if need be.

Now these tools are pretty basic. Preview adjustments don’t include advance tools in iPhoto like noise reduction, shadow and highlight adjustments, nor the ability to copy and paste adjustments from one photo to the next, but overall the tools are useful and pretty easy to use.

Adjustments Are Destructive

Finally, I would add that Preview is not of course an image management application like iPhoto. The adjustments you make to images in Preview can be destructive. In iPhoto, all your original images are retained no matter how many adjustments you make to images inside the application. However, with Preview, you will need to make a duplicate copy of the original image before you edit photos, or do a Save As in order to retain the original after the adjustments are made.

Preview is no replacement for iPhoto or other more advanced image adjustment programs, but because it’s a default application in all recent Mac operating systems, it makes for a lightweight and easy to use image editing program, and it doesn’t cost you a dime extra to use.

Let us know if you have used Preview to make image adjustments. Did you find it useful, why or why not?

1) Make a duplicate of the original image
2) Select the portion that you want to keep
3) "Invert Selection," which will cause everything to be selected except the portion you selected
4) "Delete," which deletes everything except the portion you originally selected